Carlos's credit card has an APR of 14.78% and a grace period of 18 days, and Carlos pays his balance in full every month. If his last billing cycle ended on March 28, 2010, and he made his payment on April 13, 2010, did he owe any interest on his last statement's balance? A. Yes, because he didn't pay within the grace period.

Carlos wouldn't owe any interest because he paid with the 18 day grace. He paid on the 16th day.

No, Carlos would not owe any interest on his last statement balance because he paid off his credit card within his billing cycle grace period. As long as the individual pays the amount due within the grace period allotted, no interest will be charged on the funds. A grace period is the amount of time between when the bank or organization would like payment and when they will consider the payment as late.